Audio system



FIG. 1 is a front perspective view of an audio system as seen from the front and side;

FIG. 2 is a rear perspective view thereof, as seen from the rear, opposite side, and top;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is an opposite side view thereof; and,

FIG. 8 is a side view thereof. 

CLAIM The ornamental design for an audio system, substantially as shown and described. 